Book Image

Android Application Development Cookbook - Second Edition

By : Kyle Mew
Book Image

Android Application Development Cookbook - Second Edition

By: Kyle Mew

Overview of this book

The Android OS has the largest installation base of any operating system in the world; there has never been a better time to learn Android development to write your own applications, or to make your own contributions to the open source community! This “cookbook” will make it easy for you to jump to a topic of interest and get what you need to implement the feature in your own application. If you are new to Android and learn best by “doing,” then this book will provide many topics of interest. Starting with the basics of Android development, we move on to more advanced concepts, and we’ll guide you through common tasks developers struggle to solve. The first few chapters cover the basics including Activities, Layouts, Widgets, and the Menu. From there, we cover fragments and data storage (including SQLite), device sensors, the camera, and GPS. Then we move on more advanced topics such as graphics and animation (including OpenGL), multi-threading with AsyncTask, and Internet functionality with Volley. We’ll also demonstrate Google Maps and Google Cloud Messaging (also known as Push Notifications) using the Google API Library. Finally, we’ll take a look at several online services designed especially for Android development. Take your application big-time with full Internet web services without having to become a server admin by leveraging the power of Backend as a Service (BaaS) providers.
Table of Contents (23 chapters)
Android Application Development Cookbook Second Edition
Credits
Disclaimer
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

How to schedule an alarm


Android provides AlarmManager to create and schedule alarms. Alarms offer the following features:

  • Schedule alarms for a set time or interval

  • Maintained by the OS, not your application, so alarms are triggered even if your application is not running, or the device is asleep

  • Can be used to trigger periodic tasks (such as an hourly news update), even if your application is not running

  • Your app does not use resources (such as timers or background services), since the OS manages the scheduling

Alarms are not the best solution if you need a simple delay while your application is running, for example, a short delay for a UI event. For short delays, it's easier and more efficient to use a Handler, as we've done in several previous recipes.

When using alarms, keep these best practices in mind:

  • Use as infrequent alarm timing as possible

  • Avoid waking up the device

  • Use as imprecise timing as possible—the more precise the timing, the more resources required

  • Avoid setting alarm times based...